ETIDIOH - NEW

  10 December 2025 Situation at a glance Seasonal influenza (‘the flu’) is an acute respiratory infection caused by influenza viruses that circulate globally and year-round.  It can cause illness ranging from mild to severe , sometimes resulting in hospitalization or death.  Seasonal influenza activity has increased globally in recent months, with an increased proportion of seasonal influenza A(H3N2) viruses being detected.  This rise coincides with the onset of winter in the northern hemisphere and an increase in acute respiratory infections caused by influenza and other respiratory viruses typically observed at this time of year.  Although global activity remains within expected seasonal ranges , early increases and higher activity than typical at this time of year have been observed in some regions.  Seasonal influenza viruses, including A(H3N2) viruses, continually evolve over time.  Since August 2025, there has been a rapid increase of A(H3N2) J.2...

  Abstract We describe the clinical symptoms and epidemiologic characteristics of a patient infected with avian influenza A(H10N3) virus in Guangxi Province , China , in December 2024. Whole-genome sequencing showed that the virus was highly homologous to a virus from Yunnan Province . H10 subtype viruses should be monitored for potential zoonotic or reassortant events. {From Emerging Infectious Diseases Journal, US CDC.} Sources:  Link:  https://pubmed.ncbi.nlm.nih.gov/41237415/ ____

  Abstract The development of T-cell-based influenza vaccines relies on eliciting broad CD8+ T-cell immunity, wherein T stem cell-like memory (TSCM) cells serve as the ultimate long-lived reservoir for immune memory, thereby unlocking the potential for durable protection against viral drift and shift. However, the specific immunological cues that drive the robust expansion and functional preservation of this self-renewing, multipotent subset remain unknown. Here, utilizing multi-omic systems immunology in a pediatric cohort immunized with live attenuated influenza vaccine , we identified the determinants governing the expansion of influenza virus-reactive TSCM cells . We show that a pre-existing state of innate antiviral readiness , defined by a plasmacytoid dendritic cell-associated type I interferon signature , is the requisite condition for a robust TSCM expansion. Mechanistically, this baseline innate state enhances antigen priming and enforces a qualitative divergence in T-cel...

{Greylag Goose} {Mallards} A Greylag Goose, two Mallards  in Aqmola Region. Source:  Link:  https://wahis.woah.org/#/in-review/7093 ____

  The outbreak affecting captive birds was in an establishment with 4 laying hens , 1 cock and 1 runner duck located in Harju county, Viimsi parish . The outbreak was confirmed on the 9th of December 2025 based on analysis performed tracheal and brain samples at the National Centre for Laboratory Research and Risk Assessment, and in accordance with the case definition. Measures were only applied in the outbreak establishment. Based on a risk assessment, no restricted zone was established around the affected establishment in accordance with Article 21(3)(g). The establishment concerned kept only 6 captive birds and they had no direct or indirect contact with poultry or other establishments keeping captive birds . In the establishment, all captive birds were already dead. No culling was necessary. Preliminary cleaning and disinfection was applied. Source:  Link:  https://wahis.woah.org/#/in-review/7092 ____

  Abstract Wild migratory birds play a major role in the global spread of viruses, yet the diversity, host range and transmission patterns of viruses harboured by migratory species in Aotearoa/New Zealand remain largely unknown . This knowledge gap is critical given New Zealand's position along major migratory flyways spanning Oceania, Antarctica and east Asia , where understanding viral diversity is key to assessing the risk of viral introductions such as highly pathogenic avian influenza virus and viral dispersal across these regions. To address this, we conducted the first large-scale metatranscriptomic survey of wild birds from New Zealand and its subantarctic islands , collecting 1,348 samples from 31 host species spanning four avian orders . We identified 118 avian viruses from 17 families , including 107 novel species , greatly expanding our knowledge of avian viral diversity. Viral communities differed significantly by host order and foraging behaviour, with scavenger birds...

  Abstract Highly pathogenic avian influenza H5N1 rarely infects mammals. In 2024-2025, however, genotypes B3.13 and D1.1 caused two independent spillovers into U.S. dairy cattle . By analysing 26,930 complete H5N1 genomes from global surveillance , we identified 73 major viral groups , most of which show continent-specific distribution in Europe, Asia, Africa , and North America . North American viruses exhibit higher genetic diversity in specific viral segments , including variants potentially associated with mammalian adaptation . Both dairy-cattle-associated B3.13 and D1.1 genotypes originate from the same geographic macro-area , suggesting a possible regional hotspot where avian-mammalian interfaces may facilitate viral adaptation. Our findings place the U.S. outbreaks in a global framework and indicate that North American H5N1 may be predisposed to cross-species transmission. Competing Interest Statement The authors have declared no competing interest. Funder Information Decl...

  Abstract Efficient replication of influenza A viruses (IAVs) requires balanced activities of hemagglutinin (HA), neuraminidase (NA), and the RNA polymerase complex, whose functions are strongly influenced by PB2 mutations . We previously revealed three distinct evolutionary pathways for PB2 mutations, with two pathways leading to the emergence of viral strains responsible for human seasonal infections and the 2009 pandemic , and a third pathway giving rise to H5Nx highly pathogenic avian influenza viruses (HPAIVs) defined by a triad of mutations (I147T, K339T, and A588T) that occasionally spill over to humans . Here, we investigated the zoonotic risk posed by this triad and elucidated its evolutionary relationship with HA, NA, and vaccination . Recombinant PR8 and clade 2.3.2.1c H5N1 viruses carrying the triad replicated efficiently in embryonated chicken eggs and had moderate replication efficiency in mammalian cells ; moreover, mice infected with these viral strains exhibited m...

  A Common Teal in Jeollanam-do Region. Source:  Link:  https://wahis.woah.org/#/in-review/7034 ____

  {England, Kent} Laying flock with around 31K birds. Samples taken were positive for HPAI H5N1. Birds presented clinical signs prior to testing. {England, Suffolk} Backyard flock. Samples taken were positive for HPAI H5N1. Birds presented clinical signs of AI prior to testing. Source:  Link:  https://wahis.woah.org/#/in-review/7081 ____

  Summary Background Chikungunya outbreaks have recurred in Brazil since 2014 . Building on earlier 28-day post-vaccination data , we now report 12-month safety and immunogenicity results of the VLA1553 vaccine in Brazilian adolescents. Methods In this double-blind, randomised, placebo-controlled, phase 3 trial , generally healthy adolescents aged 12–17 years were recruited at ten sites across Brazil. Individuals were excluded for immune-mediated or chronic arthritis or arthralgia, who are are immunologically compromised, or any recent live vaccines. Random allocation via simple block randomisation in a 2:1 ratio was stratified by baseline IgG and IgM serostatus by ELISA to receive a single intramuscular dose of VLA1553 or placebo . Assessed in the per-protocol population 28 days after vaccination, the primary endpoint was the proportion of baseline seronegative participants with chikungunya virus neutralising antibody levels assessed by a serum dilution achieving a 50% plaque redu...

  Abstract The unprecedented 2.3.4.4b. A(H5N1) outbreak in dairy cattle, poultry, and spillover to humans in the United States (US) poses a major public health threat. Population immunity is a critical component of influenza pandemic risk assessment . We assessed the pre-existing cross-reactive immunity to 2.3.4.4b A(H5N1) viruses and analyzed 1794 sera from 723 people (0.5–88 yrs) in multiple US geographic regions during 2021–2024. Pre-existing neutralizing and hemagglutinin (HA)-head- binding antibodies to A(H5N1) were low , but there were substantial cross-reactive binding antibodies to N1 neuraminidase (NA) of 2.3.4.4b A(H5N1). Antibodies to group 1 HA stalk were also prevalent and increased with age . A(H1N1)pdm09 infection and influenza vaccination did not induce neutralizing antibodies to A(H5N1) viruses but induced significant rise of functional NA inhibition (NAI) antibodies to N1 of 2.3.4.4b A(H5N1), and group 1 HA stalk antibodies . Moreover, pre-pandemic stockpiled 2.3....

  Abstract Adding to the global burden of high pathogenicity avian influenza (HPAI) H5N1, an unprecedented five HPAI H7 outbreaks occurred globally in 2024 . Of these, three occurred in southeast Australia , with the independent emergence of HPAI H7N9, H7N8, and H7N3 , resulting in the destruction of 2 million poultry . Historical data demonstrates that H7 outbreaks in Australia do not occur randomly , rather, there is a strong association between the timing of the previous H7 outbreaks and rainfall patterns in southeastern Australia. We aimed to address a hypothesis wherein prior to H7 outbreaks in poultry, there was a detectable change in H7 prevalence and/or virus diversity in wild bird populations . We addressed this using virological and serological surveillance data generated from multiple programs. Despite the collection of thousands of samples, there was only weak evidence to support our hypothesis, which provides strong incentive to evaluate current surveillance approaches...

  {Summary} Highlights     • All clades of the monkeypox virus (MPXV) continue to circulate.  - When mpox outbreaks are not rapidly contained and human-to-human transmission is not interrupted, there is a risk of sustained community transmission .   • In October 2025, 44 countries , across all WHO regions, reported a total of 2501 new confirmed mpox cases , including 12 deaths (case fatality ratio [CFR] 0.5%).  - About 75% of these cases were reported in the African Region .  - All regions, apart from the South-East Asia Region observed a decline in confirmed cases in October, compared to September 2025.      • Twenty-one countries in Africa have reported active transmission of mpox in the last six weeks (12 October – 23 November 2025), with 1734 confirmed cases , including 10 deaths (CFR 0.6%) reported during this period.  - Countries reporting the highest number of cases in this period are the Democratic Republic of the Congo...

  Abstract Background :  Genomic surveillance of human seasonal influenza viruses is an essential component of the Global Influenza Surveillance and Response system (GISRS) and informs the recommendations for the seasonal influenza vaccine composition. Phylogenetic analysis of viral genome sequences is used to identify groups of viruses sharing potential antigenic change and computational models are used to predict which viral variants are likely to circulate at high levels in upcoming seasons. To facilitate discussion and reporting of genetic diversity , as well as to communicate antigen recommendations , up-to-date and sufficiently granular definitions of genetic clades are important.  Methods :  A nomenclature system for segments 4 (haemagglutinin) and 6 (neuraminidase) of human A(H3N2), A(H1N1)pdm09, and influenza B .  Results :  We devised a clade suggestion algorithm that proposes new subclades based on criteria including (i) the number of sequences i...

  Latest update The UK Health Security Agency (UKHSA) has identified a new recombinant mpox virus in England in an individual who had recently travelled to Asia .   -- Genomic sequencing showed that the mpox genome contained elements of clade Ib and IIb mpox .  -- This is not unexpected as both clades are circulating , but highlights the continued potential for mpox virus to evolve and the importance of continued genomic surveillance.     -- UKHSA continues to assess the significance of the strain.   Dr Katy Sinka, Head of Sexually Transmitted Infections at UKHSA, said:    '' Our genomic testing has enabled us to detect this new mpox strain . It’s normal for viruses to evolve, and further analysis will help us understand more about how mpox is changing.   '' Although mpox infection is mild for many, it can be severe . Getting vaccinated is a proven effective way to protect yourself against severe disease, so please make su...

  Abstract Influenza remains a significant global public health concern. Live-attenuated influenza vaccines (LAIVs) are recognized as effective interventions for influenza prevention. Currently, two types of LAIVs are licensed for human use: one developed through cold-adapted viral gene mutation and the other through the deletion of the viral NS1 gene . However, the similarities and differences in these two LAIVs’ efficacy, safety, and immune responses have not been thoroughly studied. This study constructed a gene-deficient live-attenuated vaccine strain, CA4-dNS1, and a gene locus-mutated attenuated vaccine strain, CA4-cold , to compare their in vivo and in vitro replication capacity , broad-spectrum protective efficacy , safety, and immunogenicity . The results showed that both LAIVs provide comparable broad-spectrum protection against lethal H1N1 and H5N1 influenza challenges in mice and induce similar humoral and mucosal immune responses . Notably, the CA4-cold vaccine strain ...

{Excerpt} Country 2024 (cases - deaths) - 2025 (cases - deaths) - Total (cases - deaths) 1) Australia - 1 - 0 - 0 - 0 - 1 - 0   2) Azerbaijan - ... - ... - 0 - 0 - 8 - 5  3) Bangladesh - ... - ... -  3 - 0 - 11 - 1  4) Cambodia - 10 - 2 - 17 - 8 - 89 - 51  5) Canada - 1 - 0 - 0 - 0 - 2 - 1  6) Chile - ... - ... - 0 - 0 - 1 - 0  7) China - 1 - 0 - 1 - 0 - 57 - 32  8) Djibouti - ... - ... - 0 - 0 - 1 - 0  9) Ecuador - ... - ... - 0 - 0 - 1 - 0  10) Egypt - ... - ... - 0 - 0 - 359 - 120  11) India - ... - ... - 2 - 2 - 3 - 3  12) Indonesia - ... - ... - 0 - 0 - 200 - 168  13) Iraq - ... - ... - 0 - 0 - 3 - 2  14) Lao People's Democratic Republic - ... - ... - 0 - 0 - 3 - 2  15) Mexico - ... - ... - 1 - 1 - 1 - 1  16) Myanmar - ... - ... - 0 - 0 - 1 - 0  17) Nepal - ... - ... - 0 - 0 - 1 - 1  18) Nigeria - ... - ... - 0 - 0 - 1 - 1  19) Pakistan - ... - ... - 0 - 0 - 3 - 1  20) Spain - ... - ...

  Public Domain. Source:  Link:  https://www.wikiart.org/en/dante-gabriel-rossetti/the-blessed-damozel-1878 ____